A popular format for email messages is defined by the Multipurpose Internet Mail Extensions (MIME) standard. The MIME standard allows email to contain multi-part messages. MIME conformant email messages typically contain a header section and a body section. The header includes information regarding the sender, the receiver, a subject line or summary, the time and date that the message was originally sent and other information about the email. The body contains one or more entities, such as message text and file attachments of various types.
In distributed systems, electronic messages are passed from processor to processor in a store and forward manner to deliver the email message. It is not uncommon for email messages to undergo multiple processing steps during the delivery process. Typically, during each processing step, the MIME message (i.e., MIME conformant email message) is modified during this process, the MIME message is parsed, modified, reconstructed, MIME formatted, and passed to the next processing step. The process of parsing, modifying, reconstructing, and formatting can occur several times during a delivery process on a single processor. For example, a message can be virus-scanned, converted from one form to another, header fields can be added, and text disclaimer can be appended to a message text. Also a message can be deferred, if the next processor is not ready to accept responsibility for delivering a message. In such a case the message is stored and re-loaded later. The process of parsing, modifying, reconstructing, and formatting can be time consuming and inefficient.